Mold forming method and apparatus



Dec. 7, 1965 L. L. .JOHNSTON 3,221,377

MOLD FORMING METHOD AND APPARATUS Filed June 5, 1963 2 Sheets-Sheet 1Fig.|. 48

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Dec. 7, 1965 L. l.. JOHNSTON 3,221,377

v MOLD FORMING METHOD AND APPARATUS Filed June 5, 1963 2 Sheets-Sheet 2FigQz.

INVENTOR Loyal L. Johnston United States Patent O 3,221,377 MLD FRMINGMETHOD AND APPARATUS Loyal I... Johnston, Zelienople, Pa., assigner toHerman Pneumatic Machine Company, Pittsburgh, Pa., a corporation ofPennsylvania Filed .lune 5, 1963, Ser. No. 285,642 14 Claims. (Cl.22-17) The present invention relates to a mold forming method andapparatus and particularly a method and apparatus for forming foundrymolds out of nely divided mold forming material such as foundry sand.The present invention is related to and also embodies improvements overa number of my copending applications including applications Serial Nos.118,001, now Patent 3,165,794, issued January 19, 1965, and 118,002,tiled June 19, 1961, now abandoned and Serial No. 199,079, iiled May 31,1962, now Patent 3,169,284.

One of the features of the present invention is a method of forming afoundry mold by moving a former through nely divided mold formingmaterial in a ilask and additionally compacting the mold formingmaterial at the end of the flask where the former enters as the for-merenters the flask to suiciently consolidate the mold forming materialwhich is being formed into a foundry mold that the mold forming materialitself acts to guide the former as it advances through the flask. Thisenables great simplification of the apparatus and reduction in its cost.Such method has particular utility when the former is pulled through theflask as then a relatively short former can be employed which does nothave at its trailing end a long guiding element to maintain the formerin a straight path as it moves through the ask. A relatively shortguiding element may be utilized on the yformer to insure that at thevery beginning of its movement through the flask the former is confinedto its proper path, or a trailing guiding element on the former may beeliminated entirely.

I have also incorporated in the apparatus certain improvements whichfacilitate the mold forming operation and contribute to production of asuperior mold and also to economy of operation. I provide closure meansat the end of the flask towardwhich the former moves as it advancesthrough the flask `for preventing mold for-ming material from beingejected at that end of the ilask together with means (apart from theformer) for moving the closure mean-s to inoperative position to permitthe former to pass out of the flask and subsequently at the proper timein the cycle returning thel closure means to operative position. I alsoprovide tension means acting between the portions of the apparatus atthe respective ends of the flask to resist the tendency of such portionsof the apparatus to move apart during useA of the apparatus whichenables supporting means for portions of the apparatus to beeconomically designed to carry only static load.

Finally I provide mold forming apparatus comprising a ask, a base uponwhich the ask is adapted to stand in generally upright position, acylinder, means independent of the base supporting the cylinder inposition spaced above the base, a generally vertically operable pistonin the cylinder, the piston carrying holding means adapted upon downwardmovement of the piston in the cylinder to engage the upper end of theflask to hold the flask down against the base, a former, means formoving the former upwardly through the flask when the flask is standingon the base to form a mold for casting in mold forming material in theask and generally upright tension means connected at the bottom thereofto the base and at the top thereof to the cylinder resisting the upwardreaction thrust of the cylinder when the piston is 3,221,377 PatentedDec. 7, 1965 acted upon by uid under pressure in the cylinder to pressthe holding means downwardly against the base so that the supportingmeans supporting the cylinder may be designed to carry only the staticload of the cylinder and the mechanism carried thereby.

Other details, objects and advantages of the invention will becomeapparent as the following description of a present preferred embodimentthereof and a present preferred method of practicing the same proceeds.

In the accompanying drawings I have shown a present preferred embodimentof the invention and have illustrated a present preferred method ofpracticing the same, in which FIGURE 1 is an axial cross-sectional viewthrough mold forming apparatus constructed in accordance with myinvention with portions cut away for clarity and to reduce the overallheight of the gure;

FIGURE 2 is a transverse cross-sectional View taken on the line II-II ofFIGURE 1;

FIGURE 3 is a transverse cross-sectional view taken on the line III-IIIof FIGURE l; and

FIGURE 4 is a transverse cross-sectional view taken on the line IV-IV ofFIGURE l.

Referring now more particularly to the drawings, I provide a suitablefoundation a portion of which is shown in chain lines in FIGURE 1 anddesignated generally by reference numeral 2. Fixedly mounted upon thefoundation is a cylinder 3 having its axis vertical and closed at thetop by a cylinder head 4 fastened to the cylinder by screws 5. At itsbottom the cylinder 3 has a central aperture 6 in which is mounted aflanged sleeve 7 fastened to the cylinder by screws 8. Sealing rings 9are mounted in the inner face of the sleeve 7. The cylinder head 4 has aaperture 10, and sealing rings 11 are mounted in the inner face of thecylinder head 4.

A piston 12 is disposed in the cylinder 3 and sealed to the cylinderwall by sealing rings 13. The piston 12 has a hollow downward projection14 at its bottom which passes through the sleeve 7 and is sealed theretoby the sealing rings 9. Adjustable nuts 15 and 16 are threaded onto theprojection 14 and upon movement of the piston 12 in the cylinder 3 areadapted to engage a bumper 17 to limit the extent of movement of thepiston 12 in the cylinder 3. The piston 12 has an upward projection 18which passes through the aperture 10 in the piston head 4 and is sealedthereto by the sealing rings 11. Fluid under pressure is admitted intothe cylinder 3 below the piston 12 to raise the piston when desired.When the uid is exhausted from below the piston 12 in the cylinder 3 thepiston and the mechanism carried thereby move downwardly by gravity. Iffound necessary or desirable downward movement of the piston 12 may beeffected or assisted by fluid under pressure admitted to the cylinder 3above the piston 12. Upward movement is limited by engagement of the nut16 with the bumper 17 and downward movement is limited by engagement ofthe nut 15 with the bumper 17. As the parts are shown in the drawing thepiston 12 is in its lowermost position permitted by the nut 15 in theadjusted position shown.

The cylinder 3 has circumferentially spaced upward extensions 19carrying a ring 20 which is fastened to the extensions 19 by screws 21.At its upper face adjacent its inner periphery the ring 20 carries aflask seat or base 22. The ring 20 also carries ilask centering means 23fastened thereto by screws 24 which may be a cornplete annulus orcircumferentially spaced centering members.

Threaded to the upward projection 18 of the piston 12 at 25 is a hubpattern 26 which is of annular shape with an outer upwardly and inwardlyinclined face 27 of proper shape to form a hub and an axialfrusto-conical bore 28 with its larger end at the top and its smallerend at the bottom. The hub pattern 26 has an upwardly facing shoulder26a upon which is disposed a sealing ring 26b which seals the hubpattern 26 to the ask seat or base 22 in the position of the parts shownin FIGURE 1 and which as the hub pattern moves upwardly into the flaskpresently to be described seals the hub pattern to the flask. Also thesealing ring 26h and the face 27 of the hub pattern 26 constitute moldforming material com- -pacting means having an important functionpresently to be described.

A former designated generally by reference numeral 29 is shown in FIGURE1 as seated upon the hub pattern 26 with a frusto-conical downwardprojection 30 tting into the upper end of the bore 28. The former 29 hasa shoulder 31 which seats atop the hub pattern 26. The hub pattern andthe lower portion of the former are shaped to closely intert as shown sothat the former is accurately positioned by the hub pattern when seatedthereon.

The former is shown as being of thetype disclosed in my said applicationSerial No. 199,079 having Zones a, b and c Whose outer surfaces arerespectively inclined to theaxis of the former at progressively smallerangles and a cylindrical zone d adjacent the shoulder 31. The functionsof the various zones of the former are fully explained in applicationSerial No. 199,079 and therefore will not be repeated here.

The former 29 has therethrough an axial bore 32. A rod 33 extendsthrough the bore and upwardly from the former 29, the bottom end 34 ofthe rod 33 being threaded and being screwed into an internally threadedsocket 35 in a guiding member 36 which by the rod is held against thebottom of the former 29 with an interposed gasket 36a. The guidingmember 36 has a downwardly projecting guide pin 37 guidingly receivedwithin a bore 38 in the piston 12. The bottom of the pin 37 is chamferedat 39 to ease the entry of the pin into and through the hub pattern 26and into the bore 38 when the former 29 is lowered relatively to the hubpattern. Also, as the former is moved upwardly relatively to the hubpattern it is initially guided for a short distance by the guidedrelationship of the pin 37 in the bore 38. While 1 prefer to utilize theguide pin 37 in the bore 38 as just explained that guide pin is notessential and can be dispensed with in view of the compacting of themold forming material which itself forms a guide for the former asmentioned above and as will be more specically described below.

Seated on the ask seat or base 22 is a flask 40 which is somewhatoutwardly flared adjacent its lower end as shown in FIGURE l but whichotherwise is of generally cylindrical shape. The flask 40 has acentering and seating portion 41 at its bottom which seats on the flaskseat or base 22 and is centered by the centering means 23 as shown. Theportion 41 of the flask is chamfered at 42 to facilitate its entry intothe centering means 23. Permanently connected with the flask at itsupper end so as in effect to form an integral part of the flask is aring 43.

Referring now to the upper portion of the apparatus viewing FIGURE 1,there are provided any suitable supporting means shown in chain linesand designated generally by reference numeral 44 which support acylinder 45 shown as having a ange 46 seated atop the supporting means44. The supporting means 44 may be designed to carry only the staticload of the cylinder 45 and the mechanism carried thereby as thatcylinder is connected with the cylinder 3 by tension rods 47 which holddown the cylinder 45 when the reaction force exerted by the pistontherein presently to be described tends to cause it to rise. Anysuitable number of the tension rods 47 disposed about the axis of theapparatus are provided.

A piston 48 operates in the cylinder 45 and is sealed to the cylinderwall by sealing rings 49 A top cylinder head 50 is fastened to thecylinder 45 by screws 51 and a bottom cylinder head 52 is fastened tothe cylinder 45 by screws 53. The piston 48 has reduced upwardly anddownwardly extending portions 48a and 48b respectively which are sealedto the cylinder heads 50 and 52 by sealing rings 54 and 55. The piston48 is double-acting means being provided for introducing fluid underpressure both above and below the piston to positively move it eitherdownwardly or upwardly.

Threaded to the bottom of the piston 48 is a mounting member 56 havingan upper annulus 57, a lower annulus 58 and circumferentially spacedvertical posts or columns 59. A spigot former 60 is threaded into theannulus 58 as shown and centering means 61 which may be either anannulus or a plurality of circumferentially spaced centering members arebolted to the annulus 58 by bolts 62. The spigot former 60 seats at 63atop the ring 43 forming the upper extremity of the flask 4i), thespigot former being centered to the flask both by its engagement insidethe ring 43 and by the engagement of the centering means 61 outside thering 43. When fluid under pressure is admitted to the cylinder 45 abovethe piston 48 the spigot former is pressed down against the top of theflask and the flask is thus held down rmly against the flask seat orbase 22 and centered by the centering means 23 and 61.

The upper faces of the lower annulus 5S of the mounting member 56 andthe spigot former 66 are coplanar, and a spider 66 having radialspoke-like elements 69 which extend inwardly between the posts 59 mayseat thereon. The spider 66 carries a sealing ring 67 having acylindrical bore as shown and a conically tapered outer face 68 at itslower portion adapted to seat snugly within the spigot former 60 asshown. The sealing ring 67 is carried by the elements 69 through shearpins 76 so that the sealing ring 67 in normal operationis connected withthe spider 66 and is in effect integral therewith. The reason foremploying shear pins will be presently explained.

The outer extremities of two opposed radial spoke-like elements 69 ofthe spider 66 are offset upwardly as shown in FIGURE 1 and an extension64 is fastened to each thereof by screws 65 so that the under surface ofeach of the extensions 64 is coplanar with the under surfaces of theradial spoke-like elements 69 whereby the inner edges of the extensions64 seat on the annulus 58.

Connected with the upper annulus 57 of the mounting member 56 by screws71 are opposed extensions or arms 72 having bores 73 containing bushings74 through which the tension rods 47 pass as shown. Each extension 72carries a cylinder 75 arranged with its axis vertical and seated atopthe extension and fastened thereto in any suitable manner. Pistons 76operate in the respective cylinders 75 and extend downwardly through thebottom cylinder heads 77 and through bores 78 in the extensions 72 andare connected at their lower ends at 79 as shown with the extensions 64.The pistons 76 are double-acting and fluid under pressure may beadmitted either above or below the pistons; Control means are providedfor admitting and releasing fluid under pressure to and from all of thecylinders 7S simultaneously so that the pistons 76 operate insynchronism. When the pistons 76 are forced downwardly the extensions 64with the spider 66 connected therewith are pressed downwardly to rmlyseat the sealing ring 67 in the spigot former 60. When the pistons 76are moved upwardly in the cylinders 75 the extensions 64, the spider 66and the sealing ring 67 are raised so that the sealing ring movescompletely out of the spigot former 60 and to a position spaced asubstantial distance upwardly therefrom. Guide rods 80 pass through theextensions 72 and are threaded into the annulus 58 and pass throughhushed guides 81 forming part of the extensions 64.

Disposed within the mounting member 56 is an inner mounting member 82having circumferentially spaced vertical posts or columns 83 which passbetween the spokeflike elements 69 of the spider 66 and carry at theirupper portions a ring 84 supporting against an inclined shoulder 92 nearthe bottom of the piston 48 an annulus 85 within which is a guidebushing 86. The guide bushing 86 has a friction fit in the annulus 85.The inside diameter of the annulus 85 is greater than the maximumoutside diameter of the former 29 for a purpose to be presentlyexplained. A sand displacing tube 87 is disposed about the rod 33 and atits lower end receives the nose of the former 29 and at its upper end isclosed by a plate 88 and is held in position by a nut 89 threaded ontothe rod 33 so that the tube 87 is maintained in position between thenose of the former 29 and the nut 89. At its upper extremity the rod 33is connected at 9i) with a flexible tension member 91 which may be arope, cable or wire which extends to a winch which is not shown in thepresent drawings but is shown in the drawings of applications SerialNos. 118,001 and 118,002.

At the beginning of a cycle the piston 12 is in its lowermost positionas shown in FIGURE l with the nut 15 seated on the bumper 17. Theadjustment of the nut 15 determines the position of the hub pattern 26at the beginning of the cycle. Such position determines the quantity ofuncompacted finely divided mold forming material which the fiask willcontain at the beginning of the cycle which quantity of uncompactedfinely divided mold forming material in the flask in turn determines thehardness to which the mold forming material in the lower portion of theiiask is compacted while insuring formation of a mold for the casting ofa pipe of desired length.

At the beginning of the cycle the piston 48 is in its uppermost positionas are also the pistons 76. This means that the spigot former 60 iswithdrawn upwardly a substantial distance above the position in which itis shown in FIGURE l and the sealing ring 67 is drawn up toward theupper portion of the mounting member 56. The former 29 is drawn up to aposition with its zone d within the spigot former 60 and at an elevationsuch that the bottom of the pin 37 is above the elevation at which thetop of the iiask 40 is shown in the drawing.

With the parts thus positioned the empty flask 40 is set atop the iiaskseat or base 22 and centered by the centering means 23. Thereupon theformer 29 is lowered until it seats on the hub pattern 26 as shown. Theflask is then filled with finely divided mold forming material such asfoundry sand which occupies the annular space within the ask and aboutthe former seated on the hub pattern and about the tube 87. Thereuponthe piston 48 is moved down to the position shown with the spigot former60 in the upper end of the flask. The pistons 76 are moved down to theposition shown in FIGURE 1 disposing the sealing ring 67 in the spigotformer 60 as shown. The sealing ring 67 has a close but sliding fitabout the tube 87.

Fuid under pressure is next admitted into the cylinder 3 under thepiston 12 and raises the piston, forcing upwardly the hub pattern 26which in turn pushes upwardly ahead of it the former 29. Since a portionof the space in the flask 40 which originally contained only sand is nowoccupied by the former and hub pattern the sand sealing ring 2611 andthe face 27 of the hub pattern 26 in the lower portion of the flask 40is compressed. The mold forming material compacting means comprising thecompact the sand in the lower portion of the iiask against the outwardlyiared inner wall at the lower portion of the ask and about the former.By the time the nut 16 engages the bumper 17 the sand is tightlycompacted about the former and as the former advances it is guided bythe cylindrical portion d thereof advancing in the guideway comprisingthe compacted sand. Also the former is initially guided by the guide pin37 in the bore 38 until the guide pin rises out of the bore Whereafterthe former is guided by the compacted sand in the flask which isprogressively compacted to form a mold as the former moves upwardly.

As the former moves upwardly in the flask the tube 87 passes upwardlythrough the sealing ring 67 and the guide bushing 86. As the portion ofthe zone a of the former 29 exposed below the tube 87 approaches thespigot former 60 the unit comprising the sealing ring 67, the spider 66and the extensions 64 is moved upwardly to a position toward the upperportion of the mounted lmember 56. This allows the former 29 to pass upthrough the spigot former 60. When the cylindrical portion d of theformer 29 passes up into the spigot former 60 the piston 48 is raised inthe cylinder 45 until the bottom of the pin 37 is at the elevationdescribed at the beginning of the cycle. The piston 12 is moved down toits original position as shown at any time during the movement upward ofthe former 29. The flask with the mold formed therein is removed andreplaced by an empty tiask and the cycle is repeated.

If through improper functioning the portion of the zone a of the former29 which is outside the tube 87 strikes the sealing ring 67 while thesealing ring is in the position shown in FIGURE l the shear pins 70 willbe sheared off and the sealing ring 67 will be pushed upwardly by theformer 29. If such upward movement continues until the sealing ring 67engages the guide bushing 86 the guide bushing will be unseated from theannulus 85, thus avoiding damage to the apparatus. All that need be doneto place the apparatus in condition for further operation is to replacethe broken shear pins 70 by new shear pins.

While I have shown and described a present preferred embodiment of theinvention and a present preferred method of practicing the same theinvention is not limited thereto but may be otherwise variously embodiedand practiced within the scope of the following claims.

I claim:

1. A method of forming a foundry mold comprising advancing compactingmeans into one end of a tiask contaning mold forming material to compactthe mold forming material at said end of the iiask, by the advancingcompacting means pushing a tapered former through the mold formingmaterial at said end of the iiask t0 simultaneously start the formerthrough the flask and provide guidance for the former at said end of theflask by the mold forming material compacted by the advancing compactingmeans and further compacting mold forming material in the ask by theformer as it is pushed by the compacting means, pulling the former therest of the way through the tiask and while the former is thus beingpulled through the flask further compacting by the former the moldforming material in the tiask and guiding the former by the compactedmold forming material.

2. A method of forming a foundry mold comprising advancing compactingmeans upwardly into the lower end of a generally upright tiaskcontaining mold forming material to compact the mold forming material atthe lower end of the tiask, by the upwardly advancing compacting meanspushing a tapered former upwardly through the mold forming material atthe lower end of the ash to simultaneously start the former through theask and provide guidance for the former at the lower end of the flask bythe mold forming material compacted by the upwardly advancing compactingmeans and further compacting mold forming material in the ask by theformer as it is pushed upwardly by the compacting means, pulling theformer the rest of the way upwardly through the flask and while theformer is thus being pulled upwardly through the flask furthercompacting by the former the mold forming material in the ask andguiding the former by the compacted mold forming material.

3. A method of forming a foundry mold comprising advancing through aiiask containing mold forming material a former having means of smallertransverse cross section than the former extending forwardly therefromthrough the end of the flask toward which the former advances,maintaining said end of the flask closed about said means` and sealedthereto continuously about the entire periphery thereof to preventpassage of mold forming material out of said end of the flask. until theformer approaches said end of the flask, said end of the flask which isclosed about said means having an opening of smaller size than theformer, and while the former advances and shortly before the formerreaches said end of the flask opening said end of the flask sufficientlyto enable the former to move through said end of the flask.

4. A method of forming a foundry mold comprising pulling a formerthrough a flask containing mold forming material by a tension elementextending forwardly 'from the former through the end of the flask towardwhich the former is pulled with means of smaller transverse crosssection than the former disposed about the tension element, maintainingsaid end of the flask closed about said means and sealed theretocontinuously about the entire periphery thereof to prevent passage ofmold forming material out of said end of the flask until the formerapproaches said end of the flask, said end of the flask which is closedabout said means having an opening of smaller size than the former, andwhile the former advances and shortly before the former reaches said endof the flask opening said end of the flask sufficiently to enable theformer to move through said end of the flask.

5. Mold forming apparatus comprising a flask, a former, means foradvancing the former through the flask to form a mold for casting inmold forming material in the flask, closure means at the end of theflask at which the former passes out of the flask sealing said end ofthe flask for holding mold forming material in the flask as the formeradvances, the closure means when sealing said end of the flask beingdisposed in the path of the former, and means operable independently ofthe former for moving the closure means to inoperative position topermit the former to pass out of the flask.

6. Mold forming apparatus comprising a flask, a former, means forpulling the former through the flask to form a mold for casting in moldforming material in the flask, the pulling means passing out of theflask at the end of the flask toward which the former is pulled, closuremeans disposed about the pulling means at said end of the flask sealingsaid end of the flask for holding mold forming material in the flask asthe former advances through the flask, the closure means when sodisposed about the pulling means having an opening of smaller size thanthe former, and means operable independently of the former for movingthe closure means to inoperative position to permit the former to passout of the flask.

7. Mold forming apparatus comprising a flask, a base against which oneend of the flask bears, holding means engaging the opposite end of theflask to press the flask against the base and hold it in position, aformer, means for advancing the former through the flask in thedirection from the end of the flask which is against the base toward theend of the flask engaged by the holding means to form a mold for castingin mold forming material in the flask, closure means carried by theholding means and independent operating means for the closure means,operable when the holding means are in position holding a flask againstthe base, to move the closure means relatively to the holding meansbetween operative position preventing mold forming material from beingejected from the flask at the end of the flask engaged by the holdingmeans and inoperative position to permit the former to pass out of theflask.

8. Mold forming apparatus comprising a flask, a base upon which theflask is adapted to stand in generally upright position, holding meansmovable into position engaging the upper end of the flask to hold theflask down against the base, a former, means for advancing the formerupwardly through the flask when the flask is standing on the base toform a mold for casting in mold forming material in the flask, closuremeans carried by the holding means and separate actuating means,operable when the holding means are in position holding the flask downagainst the base, to move the closure means relatively to the holdingmeans between operative position preventing mold forming material frombeing ejected from the flask at the upper end of the flask andinoperative position to permit the former to pass out of the upper endof the flask.

9. Mold forming apparatus comprising a flask, a base upon which theflask is adapted to stand in generally upright position, holding meansmovable into position engaging the upper end of the flask to hold theflask down against the base, a former, means for pulling the formerupwardly through the flask when the flask is standing on the base toform a mold for casting in mold forming material in the flask, thepulling means passing out of the upper end of the flask, closure meanscarried by the holding means and disposed about the pulling means andseparate actuating means, operable when the holding means are inposition holding the flask down against the base, to move the closuremeans relatively to the holding means between operative positionpreventing mold forming material from being ejected from the flask atthe upper end of the flask and inoperative position to permit the formerto pass out of the upper end of the flask.

10. Mold forming apparatus comprising a flask, a base upon which theflask is adapted to stand in generally upright position, holding meansmovable into position engaging the upper end of the flask to hold theflask down against the base, a former, means for pulling the formerupwardly through the flask when the flask is standing on the base toform a mold for casting in mold forming material in the flask, thepulling means passing out of the upper end of the flask, generallytubular means of smaller transverse cross section than the formerdisposed about the pulling means, closure means carried by the holdingmeans and disposed about the generally tubular means and separateactuating means, operable when the holding means are in position holdingthe flask down against the base, to move the closure means relatively tothe holding means between operative position preventing mold formingmaterial from being ejected from the flask at the upper end of the flaskand inoperative position to permit the former to pass out of the upperend of the flask.

11. Mold forming apparatus comprising a flask, a base upon which theflask is adapted to stand in generally upright position, a cylinder,means independent of the base supporting the cylinder in position spacedabove the base, a generally vertically operable piston in the cylinder,the piston carrying holding means adapted upon downward movement of thepiston in the cylinder to engage the upper end of the flask to hold theflask down against the base, a former, means for moving the formerupwardly through the flask when the flask is standing on the base toform a mold for casting in mold forming material in the flask andgenerally upright tension' means connected at the bottom thereof to thebase and at the top thereof to the cylinder resisting the upwardreaction thrust of the cylinder when the piston is acted upon by fluidunder pressure in the cylinder to press the holding means downwardlyagainst the base so that the supporting means supporting the cylindermay be designed to carry only the static load of the cylinder and themechanism carried thereby.

12. Mold forming apparatus comprising a flask, a base upon which theflask is adapted to stand in generally upright position, a cylinder,means independent of the base supporting the cylinder in position spacedabove the base, a generally vertically operable piston in the cylinder,the piston carrying holding means adapted upon downward movement of thepiston in the cylinder to engage the upper end of the flask to hold theflask down against the base, a former', means for pulling the formerupwardly through the flask when the flask is standing on the base toform a mold for casting in mold forming material in the flask, thepulling means passing out of the upper end of the flask, closure meanscarried by the holding means and disposed about the pulling means and,when the holding means are in position holding the flask down againstthe base, movable relatively to the holding means between operativeposition preventing mold forming material from being ejected from thellask at the upper end of the flask and inoperative position to permitthe former to pass out of the upper end of the tlask and generallyupright tension means connected at the bottom thereof to the base and atthe top thereof to the cylinder resisting the upward reaction thrust ofthe cylinder when the piston is acted upon by fluid under pressure inthe cylinder to press the holding means downwardly against the base sothat the supporting means supporting the cylinder may be designed tocarry only the static load of the cylinder and the mechanism carriedthereby.

13. Mold forming apparatus comprising a llask, a base against which oneend of the ilask bears, holding means engaging the opposite end of thellask to press the flask against the base and hold it in position, aformer, means for advancing the former through the llask in thedirection from the end of the llask which is against the base toward theend of the flask engaged by the holding means to form a mold for castingin mold forming material in the flask, cylinder means carried by theholding means, piston means operable in the cylinder means and closuremeans carried by the piston means, the piston means being operable inthe cylinder means when the holding means are in position holding aflask against the base to move the closure means relatively to theholding means between operative position preventing mold formingmaterial from being ejected from the flask at the end of the flask enl0gaged by the holding means and inoperative position to permit the formerto pass out ofthe ilask.

14. Mold forming apparatus comprising a llask, a base against which oneend of the ilask bears, holding means engaging the opposite end of thetlask to press the flask against the base and hold it in position, aformer, means for advancing the former through the flask in thedirection from the end of the ilask which is against the base toward theend of the llask engaged by the holding means to form a mold for castingin mold forming material in the flask, the holding means havingplurality of outwardly extending arms, a cylinder carried by each arm, apiston operable in each cylinder and closure means carried by thepistons, the pistons being operable in the cylinders when the holdingmeans are in position holding a llask against the base to move theclosure means relatively to the holding means between operative positionpreventing mold forming material from being ejected from the llask atthe end of the ask engaged by the holding means and inoperative positionto permit the former to pass out of the llask.

Reterences Cited by the Examiner UNITED STATES PATENTS 289,035 11/1883Schickle 22-17 1,272,278 7/1918 Ladd 22-17 1,299,967 4/1919 Lemoine22-17 2,019,937 11/1935 Staples.

2,875,482 3/ 1959 Hamilton et al 22--18 FOREIGN PATENTS 544,822 2/ 1932Germany.

26,786 12/ 1906 Great Britain.

MARCUS U. LYONS, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CRRECTION Patent No.3,221,377 December 7, 1965 Loyal L. Johnston It is hereby certified thaterror appears in the above numbered patent requiring correction and thatthe said Letters Patent should read as corrected below.

Column 4, line 5, after double-acting" insert a comma; column 5, line56, for "Fuid" read Fluid line 62, strike out "sealing ring 26b and theface 27 of the hub pattern 26" and insert the same after "comprisingthe" in line 64, same Column 5; column 6, line 9, for "mounted" readmounting line 40, for "contaning" read containing line 6l, for "flash"read flask column 7, line 5, after "flask" strike out the period.

Signed and sealed this 18th day of October 1966.

(SEAIJ Attest:

ERNEST W. SWIDER EDWARD I. BRENNER Attesting Officer Commissioner ofPatents

1. A METHOD OF FORMING A FOUNDRY MOLD COMPRISING ADVANCING COMPACTINGMEANS INTO ONE END OF A FLASK CONTAINING MOLD FORMING MATERIAL TOCOMPACT THE MOLD FORMING MATERIAL AT SAID END OF THE FLASK, BY THEADVANCING COMPACTING MEANS PUSHING A TAPERED FORMER THROUGH THE MOLDFORMING MATERIAL AT SAID END OF THE FLASK TO SIMULTANEOUSLY START THEFORMER THROUGH THE FLASK AND PROVIDE GUIDANCE FOR THE FORMER AT SAID ENDOF THE FLASK BY THE MOLD FORMING MATERIAL COMPACTED BY THE ADVANCINGCOMPACTING MEANS AND FURTHER COMPACTING MOLD FORMING MATERIAL IN THEFLASK BY THE FORMER AS IT IS PUSHED BY THE COMPACTING MEANS, PULLING THEFORMER THE REST OF THE WAY THROUGH THE FLASK AND WHILE THE FORMER ISTHUS